6mm pyro...

[ETradesmen]

Hello everybody, my name is Michael.

Last week a landlord called me regarding a faulty electric shower that the company tried to re fit under warranty but told him that the cable supplying it was under rated so they couldn't finish the job...

I went to take a look and the property being a hostel type flat in London did not meet 17th edition regulations. There was no RCD present and the consumer unit was older than me (27 years). I looked at the circuit supplying the shower and it was a 6mm twin and earth on a 50amp breaker. This obviously isn't correct as the run was over 15M and the shower was 9.5KW.

Obviously a shower pulling 38amps cannot be fed via a 6mm twin and earth on a 50amp breaker unless you were after an insurance job...

So after wrestling the metal cabinet off the Crabtree fuse board I noticed it was fed via a 6mm pyro. The circuits in the board were a cooker supply, upstairs lights, downstairs lights, immersion, upstairs sockets, downstairs sockets and a shower supply... Is the 6mm pyro capable of such demand?

I couldn't gain access to the meter cupboard to see what the fuse was feeding the flat, but to me it sounds a bit under rated?

The length of run is around 30M and the cable is clipped direct...

Obviously the landlord is asking me why it needs changing if 'its worked perfectly fine all this time'. But I don't really fancy putting my name on a job if I think it's going to be on the ITV headlines the next day.

Your views are welcome.

Michael > NICEIC registered > 10 years in the business

 

[londonlec]

I'm certain a 6mm 2 core pyro is good for in excess of 50 amps! Is it MICC all the way or some twin and earth?

I haven't got the regs to hand though.

 

[Dean182]

57 Amps.

 

[ipf]

Pyro feeding the CU I'm thinking ?

 

[londonlec]

Pyro feeding the CU I'm thinking ?

Now I've re read it you may be right!

OP can you confirm what is Pyro and what is PVC..?

 

[ETradesmen]

Yep pyro feeding the CU.

You reckon 57amps?

Its all pyro (I'm assuming).

I don't think a 4KW oven, 9.5KW shower and a immersion left on 24/7 is ideal on a 6mm pyro...

Whats the working life of pyro? I know it's good and has a long working life. All the circuits are wired in the stuff.

Also, the shower switch is recessed into the architrave with no back box...

^^^ just thought I'd share with you the amazing installations in London...oh and no earth sleeving or earth terminal behind the shower switch

 

[ETradesmen]

Pyro > mineral insulated copper conductor.
PVC > twin and earth

are you a plumber?

 

[londonlec]

There is a huge difference in the current carrying capacity of PVC twin and earth and pyro, you need to find out what feeds this shower.

Don't worry about the 6mm feeding the flat, half of London is the same

The working life of a pyro is double or triple that of PVC.

 

[ETradesmen]

This topic isn't about the shower... I know how to sort that

I just don't want to get involved in something that is going to cause me grief :/

Can pyro catch on fire? Will I have enough time to close my company and re open another in my imaginary wife's name?

michael

 

[Dean182]

Why are you trying to replace something for the sake of it? Providing the fuse/breaker protecting the pyro is rated less than the current carrying capacity of the cable, what's the problem? What are the chances of the shower, immersion and oven all being on, full, at the same time?

 

[londonlec]

This topic isn't about the shower... I know how to sort that

I just don't want to get involved in something that is going to cause me grief :/

Can pyro catch on fire? Will I have enough time to close my company and re open another in my imaginary wife's name?

michael

Nothing wrong with the pyro.

 

[Guest55]

WTF is this thread about again ?
so weve established a CU is fed by 6mm pyro thats rated for 57A.
so if the fuse backing that up is less than 57 then theres no prob.
and i find it puzzling that a spark of 10 yrs asks whether pyro will catch on fire lol.

 

[ETradesmen]

I don't care about the pyro!! I care about blowing the incoming fuse and getting a call out because some polish girl is late for her cash in hand job.

It's a hostel...They don't pay for electricity...

The chances of ALL the appliances being on are high.

Ok, so say the pyro is fine. How the hell am I going to change the consumer unit when all the circuits are wired in old pyro! WHAT A HEAD ACHE.

Do I not bother about the existing consumer unit and just install a small RCD board feeding the shower?

I know how to get a round things, it was just the pyro I wasn't too keen on.

 

[ETradesmen]

Biff the only time I've used pyro is in my finals at college... >999 mega reading too!!

The fire thing was a joke.

This thread is about upgrading the sub main due to N increase in demand.

That is it...

 

[londonlec]

I give up :uhoh2: